Jang Geun-Suk was born on August 4, 1987 in Danyang County, Chungcheongbuk Province, South Korea. He is an only child. Geun-Suk started working as a child model at the age of six after he was discovered by a talent agent. At that time, Geun-Suk's parents were selling their house and the agent, who was a prospective buyer, saw Geun-Suk. Seeing his potential, the agent advised Geun-Suk's parents to allow him to try a career in modeling.

Jang Geun-Suk made his acting debut in the 1997 HBS sitcom "Selling Happiness" (Haengbokeul Pabmoda). He then continued to work in television as a child actor. In middle school, Geun-Suk heard the music of Japanese pop singer singer Ken Hirai & Japanese rock band L'Arc-en-Ciel. He was inspired enough by these bands to start learning the Japanese language by himself. In junior high school, Geun-Suk went to school in New Zealand to learn English and Japanese. Because of his studies in New Zealand, he can carry casual conversations in both languages. Even though Geun-Suk wanted to continue his studies in New Zealand, a job offer brought him back to South Korea. Geun-Suk landed a role in the popular MBC sitcom Nonstop 4. After his work in Nonstop 4, Geun-Suk fell into a self-perceived slump and didn't think his acting was good enough. He decided then to re-devote himself to becoming a true actor. In 2005, Geun-Suk's portrayal of the president's son in the SBS drama "Lovers in Prague" became a hit and was well regarded by drama fans.

In 2006, Geun-Suk made the jump to the big screen in the Japanese horror film One Missed Call Final where he played the role of a deaf boy. Using his past experience with the Japanese language, Geun-Suk was able to communicate with his Japanese co-stars with ease. He also learned sign language in preparation for his role.

Back on the small screen, he next played the role of Kim Eun-ho, Hwang Jin-yi's first love in the TV dramaHwang Jin-i. Geun-Suk's performance gained the attention of many female fans. He also starred in the KBS drama, Hong Gil Dong, as Prince Lee Changhwi. In 2007, Geun-Suk was cast in the rock music themed film "The Happy Life." His portrayal of Hyeon-ju in "The Happy Life" allowed Geun-Suk to show off his masculine charms, as well as display his skills as a singer. Geun-Suk would go on to play in two more music inspired titles in 2008, with the feature film Do Re Mi Fa So La Ti Do and the hit MBC TV drama Beethoven Virus

Geun-Suk was the top choice for the role of Goo Jun Pyo during the initial casting of Boys Over Flowers but he turned it down for Beethoven Virus.

Geun-Suk's next role in the 2009 thriller The Case of Itaewon Homicide was his first villain role. The film is based on a true story of a murder that occurred at a Burger King restaurant in Itaewon, South Korea. Geun-Suk portrayed the role of Pearson, a disturbed, young Korean-American accused of stabbing a student to death. Geun-Suk had to speak his lines in English throughout the film, a job he did well, according to BeyondHollywood.com: "Jang Keun Suk performs very well as the sullen Pearson.

Film critics and moviegoers also praised Geun-Suk for his acting. A movie review posted on LondonKoreanLinks.com said: "The casting is cleverly done with Jang Geun-suk as the ‘innocent’ accused, his popularity allowing the audience to feel some empathy and warmth to an otherwise unattractive character. He does well in this role, a break from his normal cheerful persona and, combined with the fact he has to speak English through most of the film, it’s quite impressive. Its not perfect American accent of course, but it plays a vital part in itself

In You're Beautiful, Geun-Suk played the role of Hwang Tae-Kyung, leader of rock band A.N.Jell, who falls in love with a fellow band member who is a female pretending to be a guy on behalf of her brother, played by Park Shin Hye. The show, which also starred Lee Hong Ki and Jung Yong Hwa, obtained a cult following online and became a hit in other Asian countries.

Geun-Suk was also one of the actors who appeared in the photoshoot "Kolon Christmas Photo Shoot" in 2008, along with co-actors Joo Jin Mo, Song Il-gook, Ko Soo, and Park Jae-jung. He also was a host on Tracking your X boyfriend. He's also known for his outspoken personality and tectonic dance.

Though he sings for some of his dramas, he has not released any music of his own: except for a few songs done for advertisements. "Black Engine" for Mens cosmetics and skin care, and "Touch Holic" and "Just Drag" for a new touchscreen devices.

Geun-Suk recently reunited with his You're Beautiful co-star Shin Hye to film an advertisement for Korea's Garden 5 Shopping Mall. He will next be seen in the Korean movie adaptation of Japanese drama Kimi wa Petto.